This protocol evaluates the effect of pretreatment of normal volunteers with glucocorticoids before administration of endotoxin. Subjects will be studied on 4 occasions separated by at least 2 weeks. On each occasion, they will receive two injections providing combinations of glucocorticoids or placebo during the first injection and endotoxin (E. coli,4ng/kg) or placebo during the second injection. Cytokine expression and physiological responses will be assessed.